So, if you're familiar with 1500 Vulcans then you probably know about the POG, JOG, and SOG. If you don't know or are considering a 1500 Vulcan, read up on it, here.
Anyhow, properly replacing a POG or a SOG that lost its circlip(item 480) requires splitting the cases. Obviously a major job.
So my friend Vulcan Scott had a POG and did a JOG and then lost the circlip. So he figured out a way to swap to SOG with splitting cases. I'm going to try to explain this process from what he told me and using the pictures he provided me.
Here's a picture of a POG and hell hole for reference.
Vulcan Scott practiced with the shaft of his old POG.
First off, he widened the circlip groove on the shaft of the SOG with a dremel and cut off wheel.
He then cut a nice bevel onto the end of the shaft with a dremel and grinding wheel.
Next he built a tool to hold the circlip in the hell hole during installation. It's a washer that fits over the shaft and then cut to a "C" shape. This was brazed onto a stiff wire. The circlip was "glued" to the C-washer with some sticky grease. Into the hell hole with it. Lay on your back and install the greased end of the gearshaft into the hole and turn it until the circlip finds its home. Prayers or swear words, whichever you prefer, are required during that last step.
Simple as a pimple, right?